Three-position relay



Jan. 26, 1943. A. J. M MASTER THREE-POSITION RELAY Filed July 17, 1941 2 Sheets-Sheet l Jan- 26, 194 A. J. MCMASTER 2,309,349

THREE-POSITION RELAY Filed July 17, 1941 2 Sheets-Sheet 2 Patented Jan. 26, 1943 THREE-PO SITION RELAY Archie J. McMaster, Deerfield, Ill., assignor to G-M Laboratories, Inc., Chicago, 11]., a corporation of Illinois Application July 17, 1941, Serial No. 402,801

12 Claims.

My invention relates to three-position relay constructions. It relates more in particular to an improved three-position relay and includes novel features having certain advantages when a plurality of such three-position relays are mounted in a common bank.

The principal object of my invention is the provision of an improved three-position relay.

A further object is the provision of a threeposition relay which is positive in its operation and accurately positions the parts at the normal or at-rest position, at fully actuated position, and at the intermediate position.

A further object is the provision of a threeposition relay construction whereby three-position relays may be produced in the form of banks thereof of any suitable size, in an economical manner and on a production basis using simple, conventional manufacturing processes.

A still further object is the provision of a bank of three-position relays so constructed and arranged that a circuit not normally associated with the relays may be effected in response to energization of the last one of the series of relays mounted in a bank.

Other objects and features of my invention will be'apparent from a consideration of the following detailed description, taken with the accom panying drawings, wherein Fig. 1 is a view looking at the end of a bank of relays constructed in accordance with my invention, the view showing a single relay in elevation and illustrating the position of a switch which is adapted to be actuated on energization of the last relay in the bank;

Fig. 2 is a plan sectional view taken approximately on the line 22 of Fig. 1, the view showing in plan a double armature arrangement and details of the associated switch, all except one relay being broken away to conserve space;

Fig. 3 is an enlarged sectional view taken on the line 3-3 of Fig. 1 looking in the direction of the arrows;

Fig. 4 is an elevational view showing a bank .of relays, the view being such as would be seen looking at the right hand side of Fig. 1 and being partially broken away to conserve space;

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 2 showing the parts, however, in the intermediate position; and

Fig. 6 is an elevational view of a relay unit partly in section and illustrating the position of the parts in the unactuated position.

In accordance with the main features of the invention, the relay comprises a coil with a twopart armature governing the position of a sliding actuator bar normally spring pressed in one direction but held against movement by the two-part armature. Energization of the coil serves to release the actuator bar from engagement with one armature part but to retain it in engagement with the other armature part; and subsequent de-energization of the coil, and return of the two-part armature to normal position, serves to release the actuator bar from the second armature part and permit its movement to fully actuated position. The actuator bar carries an insulating block engaging one or a plurality of contact carrying springs, and the con tacts associated with the contact carrying springs are adapted to be closed or opened so as to estab lish different circuit conditions, if desired, at each of the three positions of the actuator bar. The relays of my invention may, as previously noted, be mounted to form a block of relays, and preferably I employ a single U-shaped chassis irame supported by a pair of mounting brackets on which separately are supported the parts of single relays, including a coil supporting frame, actuator bar, and armature assembly. A rocking reset bar is provided to engage the actuator bars to return them to normal or unactuated position. I also utilize a rocking yoke so constructed and arranged that, upon actuation of the last relay of a bank of relays, a switch may be operated to control a circuit, which circuit may have the effect of returning all of the actuator bars to normal position, or to efiect any other operation desirable in the environment in which a relay or bank of relays may be employed.

Referring now to the drawings, I provide a chassis H), on opposite ends of which are secured mounting brackets II. The chassis I0 is U- shaped in cross section and is conveniently formed from a long strip of material which previously has been punched to provide for the mounting of a large number of relays, for example, twenty-four or thirty-six, and this strip is cut off to provide for the mounting of a number of relays desired for a particular installation, for example, one relay, ten, twelve or the like. The relay construction may be identical in each instance, and so, for convenience in describing the relay, I shall refer only to the mounting of a single relay in association with the chassis.

Mounted above the chassis is a coil frame l2 carrying a coil [3 having a usual type of core I4. The coil may be mounted by means of a non-magnetic screw l6, and an insulating spacer I! may be provided between the core l4 and the coil frame l2. The coil frame has a portion ll formed vertical and lying against one leg of the U-shaped chassis, and a horizontal portion is shown containing an extension on which is carried an assembly i9 comprising insulating spacers 2i and contact carrying springs 22. The coil frame 12 may be secured in position by any suitable means, and, in the drawings, I illustrate a construction wherein one or a plurality of projections 23 from the chassis frame extend through punched openings in the coil frame, so that slight twisting of the projections 23 serves to hold the coil frame in position. The vertical portion of the coil frame may be secured to the associated leg of the U-shaped chassis frame by means of screws, rivets. or the like.

Extending through slotted portions of the chassis frame is a sliding actuating bar 24 carrying an insulating block 26 with sections cut therefrom to receive selected members of a group of contact carrying springs 22. The actuator bar 24 is urged in a right hand direction, looking at Fig. 1, by a coil spring 21. one end of which is secured to a tab 28 struck downwardly from the actuator bar 24 and the other end of which is secured to the chassis frame III. Secured to the upper surface of the actuator bar 24 is a stop bracket 29, this bracket being adapted for engagement by a plural-part armature to control the position of the actuator bar in a manner to be described.

The plural-part armature comprises an upper armature member 3| and a lower armature member 32, the two armature members being spaced from each other and each being fulcrumed against a ledge formed on the vertical portion I8 of the coil frame l2, the chassis having a cut-away portion at this point. Springs 33 and 34 have their lower ends secured to the armature members II and 32, respectively, and their upper ends secured to a projection 36 from the coil frame l2, whereby to hold the upper and lower armature members normally in the positions shown in Fig. 6. The lower armature member 32 carries a headed stud 31, the shank of which extends loosely through an aperture in the upper armature member 3|, thus forming a loose or lost motion connection between their members. Each of the armature members has a central end projection adapted to extend through an opening 38 in the stop bracket 29, the projection 39 on the upper armature member 3| being substantially straight and shorter than the projection 4| on the lower armature member 32 which is curved slightly downwardly. With the parts normally in the position shown in Fig. 6, the actuator bar 24 is prevented from moving to the right because of the engagement of the stop bracket 29 by the projection 4! at a point just below the opening 38. On energizetion of the coil 13, however, the upper armature member 3| is drawn to the core l4 and the lower armature member 32, which acts as a follower, is released from engagement with the stop bracket 29. Before this release can occur, however, the projection I! of the upper armature member I! has reached a position above the opening 38 so that it now engages the stop bracket 29 so as to hold the parts in the position shown in Fig. 5. If the coil I3 is now deenergized, the upper armature member ll will be withdrawn by its spring to a lower position, but, since the projection 4| now extends through the opening 38, it is impossible for this projection 4i to contact the stop bracket 29, with the result that the projection 39 will become aligned with the opening 38 and the actuator bar 24 will be permitted to move to the position shown in F18. 1.

Each relay of a bank of relays will function in this same manner and the parts in any particular bank of relays will be identical except possibly with respect to the arrangement and disposition of the contacts controlled by the position of the actuator arm. Pivoted to the mounting brackets is a rocking reset bar 43 of generally right angular cross section and adapted, when rocked in a counter-clockwise direction, when looking at Figs. 1, 5 and 6, to engage a downwardly extending projection 44 on the actuator bar to return the actuator bar to normal position. A spring 46 has one end secured to a lower portion of the rocking reset bar and the other end secured to a tab 41 struck from a portion of one of the mounting brackets whereby to hold the rocking reset bar in the position shown in Fig. 5 out of contact with the downwardly extending projection 44. a

A yoke 44, which may be formed oi heavy wire or the like but may have any suitable construction, has its ends 49 pivoted in apertures provided in the mounting brackets and is normally urged to rotate bodily about its pivoted ends by a coil spring 5|. This coil spring, as shown in the drawings, is disposed between the rocking reset bar and the yoke 48, but other resilient means for urging the yoke in the desired direction may be employed. A tubular member 52 is shown carried by the longitudinal portion of the rocking bar. This tubular member 52 is formed of a suitable insulating material, such as rubber, which will then also have some cushioning action. with the type of switch shown, it may be omitted, but should be used it the switch used would otherwise be grounded through the relay frame. With the construction and arrangement shown, the yoke 42 is held against movement so long as any single one of the relays is unactuated or until all of the actuator bars 24 have been moved in a right hand direction looking at Fig. 1. Carried on one of the brackets II is a switch 53 shown as a type carrying a. small actuating plunger 54. A switch operating bar 58 is carried on the associated bracket II and is in a position to be engaged by one arm of the yoke 44 when the yokemoves in a. clockwise direction about its pivots. Operation of the switch 53 may, therefore, be made responsive to the actuation of the last of a series of relays. Such series of relays may be all of the relays in a bank, selected ones of them, or the switch 53 may be operated in response to operation of only a single relay of a series.

The construction, assembly, operation and advantages of the relay of my invention should be clear to those skilled in the art from the above description without additional elaboration. I wish to note, however, that the stop bracket 2! is preferably formed of non-magnetic material, or, if formed of magnetic material, should be suitably insulated such as by the use of a nonmagnetic shlm (not shown) between it and the actuator bar, or between the armature and. follower around stud 31. Both of the armature members 3| and 32 may be formed of magnetic material, or the latter, which may be thought of as a follower and not a true armature, may, if desired, be formed of non-magnetic material. I wish to point out that with the parts shown in Fig. 6, the magnetic fiux will first be effective to raise the upper armature member 3| (which, as noted, may be considered the armature proper, with the armature member 32 as its follower), thereby tending to leave the lower armature member 32 in its lower position. Should the magnetic flux be such as to tend to attract the follower, or armature member 32 also, however, the resistance to its upward movement caused by the engagement of its curved projection 4| against the stop bracket 39 would prevent its being carried upwardly because of magnetic force alone. fore, it will act as a follower, so as to be drawn upwardly by the armature 3| engaging the head of stud 31, and there will be no possibility of releasing the stop bracket 29 until the upper armature member 3| (the armature proper) is advanced far enough in its upward movement to place the projection 39 in the path of the stop bracket 29. In connection with the armature and stop bracket assemblies, it should be noted that, when the two armature members are mutually in engagement, the projections 39 and 4| will pass through the opening 38, but when they are separated their maximum distance, it is impossible for them to pass through this opening.

It will be noted, further, in the construction shown, that the fulcrums of the armature members comprise lower surfaces formed on the vertical portion l8 of the coil frame l2 formed by stepping back the said vertical portion IE to produce shoulders, as shown in Fig. 3, and extending the narrowed portion below the shoulders through transverse slots in the armature members. This construction provides a fixed fulcrum for the armature members and spaces them from each other. The actuator bar, at this side of the chassis frame, passes through a slot, the upper limit of which is defined by the extreme lower edge of the coil frame. The construction shown and described provides for definite positioning of the armature members, is simple, inexpensive, and facilitates assembly.

While the stop bracket 29 may be modified quite extensively, I wish to point out that some very definite advantages are obtained by utilizing substantially the identical arrangement shown, ora functionally fully equivalent shape. It will be noted that the nearly vertical portion of the stop bracket below the opening"38 (see Fig. is formed at an angle, so that when the follower 32 is raised, it does not have to force the actuator bar 24 against the load of spring 21. In like manner, the portion of the stop bracket above the opening 38 is formed so that when the armature 3| is moving to its de-energized position, it does not have to force the bar 24 to the left against its spring load. These two portions of the stop bracket 29 (comprising the entire generally vertical portion) may comprise arcs around centers located at the pivot points of the armature and follower. I have found, however, that I may shape these two portions of the stop bracket 29, so that there is a tendency for the load of spring 21 to urge the armature and follower in the directions in which they move on actuation, but without sufiicient bias to overcome entirely the friction of their ends against the surface of the stop bracket. This construction and arrangement lessens the effect of friction, reduces the strength requirement of spring 33, and lessens the load factor, or force to be produced by the coil l3.

Under any circumstances, there- While the relay of my invention is described as having three positions, the features described and shown have advantages when used with other types of latch relays, such as the more frequently encountered two position latch relay. Since the true armature carries no load until it encounters the head of the lost motion stud, ithas acquired considerable inertia before it encounters the resistance required to unlatch the actuator bar. The relay will, therefore, operate on less power than similar constructions which do not employ the lost motion feature, a very definite advantage. The relay may be used as shown to control two positions, or it may be modified slightly, such as by omitting the projection 39, to permit movement to the extreme position immediately upon energization of the coil l3.

It will be understood that my invention is not primarily concerned with the arrangement and construction of the contact assembly, nor is it concerned with the circuits which may be established in response to changing the positions of the contacts. The invention is concerned, however, with the fact that three distinctpositions of the actuator bar 24 may be established and that different circuit conditions may exist with respect to each one of these three positions. The insulating block 26 may be given any suitable shape depending upon what results the manufacturer or operator wishes to accomplish from a circuit control standpoint. Thus, in any bank of relays, all of the insulating blocks 26 may be identical, or each may have a different construction, without departing from any of the features of the present invention. I wish to point out also that, while my invention is particularly adaptable for use in the form of a bank of relays, the features of the three-position relay, particularly those concerned with the construction of the actuator bar, and plural-part armature, may be used where only a single relay is employed.

While the particular structural arrangements shown and described have certain advantages, the invention is not limited to the details thereof, except within the scope of the claims.

What I claim as new and desire to protect by Letters Patent of the United States is:

1. In a relay of the character described, a coil, a slidable actuator bar, sprin means for urging said actuator bar longitudinally in one direction, a stop bracket on said actuator bar, a pair of spaced armature members fulcrumed and spring biased away from said coil, projections on said armature members, one of said projections being longer than the other, and a lost motion connection between said armature members, whereby the armature member contiguous to the coil will first move alone on energization of the coil and then, through said lost motion connection, carry the other armature member with it but in spaced relation, the construction and arrangement being such that, in unactuated position, said actuator bar is held against movement by the longer of said projections engaging said stop bracket,

energization of said coil will result in releasing said longer projection from said stop bracket but align the shorter projection therewith whereby to permit said actuator bar to move to an intermediate position, and de-energization of said coil and return movement of the armature members will release the shorter projection from said stop bracket and permit movement of said actuator bar to fully actuated position.

2. In a relay of the character described, a coil, 2. slidable actuator bar, spring means for urging said actuator bar longitudinally in one direct, a stop bracket on said bar having an aperture substantially centrally disposed therein, a pair of spaced armature members fulcrumed and spring biased away from said coil, projections on said armature members adapted, when disposed in face-to-face relation, to pass through said aperture in the said stop bracket, one of said proiections being longer than the other, and curved downwardly to engage said stop bracket below said aperture and hold the actuator bar in normal unactuated position, and a headed stud carried by one armature member extending loosely through an opening in the other armature member, whereby the armature member contiguous to the coil will first move on energization of the coil and, through said stud, carry the other armature member in spaced relation, the construction and arrangement being such that, when said actuator bar is held against movement by the longer of said projections, energization of said coil will result in moving the armature member carrying the shorter projection and then carry the second armature member as a follower upwardly to align said longer projection with said aperture to permit said actuator bar to move to an intermediate position, and de-energization of said coil and return movement of the armature members will align the shorter projection with said aperture and permit movement of said actuator bar to fully actuated position.

3. In a relay of the character described, a coil, a slidable actuator bar, spring means for urging said actuator bar longitudinally in one direction, a stop bracket on said bar having an aperture therein, a pair of spaced armature members fulcrumed and spring biased away from said coil, projections on said armature members adapted, when disposed in face-to-face relation, to pass through said aperture in the said stop bracket, one of said projections being longer than the other, and a headed stud carried by one armature member extending loosely through an opening in the other armature member, whereby the armatur member contiguous to the coil will first move on energization of the coil and, through said stud, carry the other armature member in spaced relation, only one said projection adapted to pass through said aperture of the stop bracket when said projections are separated, the construction and arrangement being such that, when said actuator bar is held against movement by the longer of said projections, energization of said "oil will result in aligning said longer projection with said aperture to permit said actuator bar to move to an intermediate position, and de-energization of said coil and return movement of the armature members will align the shorter projection with said aperture and permit movement of said actuator bar to fully actuated position.

4. In a relay of the character described, a coil, in fulcrumed armature sprin pressed away from the coil, an armature follower fulcrumed to lie generally parallel to the armature and spring pressed away from said coil, a loose connection between said armature and follower so constructed and arranged that movement of the armature to the coil will initially be ineffective to move the follower, but continued movement thereof will carry the follower, a spring pressed contact actuator member having a stop portion normally urged toward said armature and follower, said stop portion having an opening generally aligned 1s with the armature and follower, a projection car ried by the armature, and a projection carried by the follower, the arrangement being such that energization of the coil will align the projection on the follower with the said opening but at the same time hold the projection on the armature out of alignment with the opening, whereby to permit movement of the contact actuator member to intermediate position, and de-energization cf the coil will then align the projection on the armature with the opening and permit the contact actuator member to move to fully actuated position, the said two projections being adapted to pass through said opening when in contact with each other, but being incapable of passing through said opening when separated a distance determined by the loose connection between the armature and follower.

5. In a relay of the character described, a coil, a fulcrummed armature spring pressed away from the coil, an armature follower fulcrumed to lie generally parallel to the armature and spring pressed away from said coil, a loose connection between said armature and follower so constructed and arranged that movement of the armature to the coil will initially be ineffective to move the follower, but continued movement thereof will carry the follower, a spring pressed contact actuator member having a stop portion normally urged toward said armature and follower, means on both the armature and follower adapted separately to engage said stop portion of said contact actuator member, the construction and arrangement of the parts being such that energization of the coil will space said armature and follower and release the stop engaging means on the follower from said stop portion but maintain the stop engaging means on the armature in contact with said stop portion, whereby to permit movement of the contact actuator membar to intermediate position, and deenerglzation of the coil will then release the stop engaging means on the armature from said stop portion and permit the contact actuator member to move to fully actuated position.

6. In a relay of th character described, a coil, a pivoted armature spring urged away from the coil, a pivoted follower positioned at that side of the armature away from the coil, said follower also being spring pressed away from the coil, 1 lost motion connection between unpivoted ends of the armature and follower, the armature, follower and lost motion connection comprising an armature-follower assembly, the parts of said armature-follower assembly being so constructed and arranged that, when the coil is de-energized, said armature and follower have their unpivoted ends in contact but energization of the coil and attraction of the armature permits a lag in the movement of the follower whereby to separate unpivoted ends 01' the armature and follower, a spring-pressed contact actuator member normally held against movement by the armature-follower assembly, said actuator member having stop means cooperating with the armature-follower assembly to permit partial movement of the actuator member when the coil is energized, and continued full movement when the coil is subsequently de-energized.

7. In a relay of the character described, a coil. a fulcrumed armature spring pressed away from the coil, an armature follower fulcrumed to lie generally parallel to the armature and spring pressed away from said coil, a loose connection between said armature and follower so constructed and arranged that movement of the armature to the coil will initially be ineffective to move the follower, but continued movement thereof will carry the follower, a spring pressed contact actuator member having a stop portion normally urged toward said armature and follower, means on both the armature and follower adapted separately to engage said stop portion of said contact actuator member, the construction and arrangement of the parts being such that energization of the coil will space said armature and follower and release the stop engaging means on the follower from said stop portion but maintain the stop engaging means on the armature in contact with said stop portion, whereby to permit movement of the contact actuator member to intermediate position, and deenergization of the coil will then release the stop engaging means on the armature from said stop portion and permit the contact actuator member to move to fully actuated position, said stop portion of the contact actuator member havin generally arcuate surfaces at parts engaged by said armature and follower, said arcuate surfaces being arcs of circles generated about centers corresponding generally with the fulcrum points of said armature and follower, respectively.

8. In a relay of the character described, a coil, a fulcrumed armature spring pressed away from the coil, an armature follower fulcrumed to lie generally parallel to the armature and spring pressed away from said coil, a loose connection between said armatur and follower so constructed and arranged that movement of the armature to the coil will initially be ineffective to move the follower, but continued movement thereof will carry the follower, a spring pressed contact actuator member having a stop portion normally urged toward said armature adapted separately to engage said stop portion of said contact actuator member, the construction and arrangement of the parts being such that energization of the coil will space said armature and follower and release the stop engaging means on the follower from said stop portion but maintain the stop engaging means on the armature in contact with said stop portion, whereby to permit movement of the contact actuator member to intermediate position, and deenergization of the coil will then release the stop engaging means on the armature from said stop portion and permit the contact actuator member to move to fully actuated position, said stop portion of the contact actuator member having generally arcuate surfaces atparts engaged by said armature and follower, said arcuate surfaces being arcs of circles generated about centers corresponding generally with the fulcrum points of said armature and follower, respectively, said arcuate surfaces, however, being slightly distorted in a direction to cause the opening of said contact actuator membet to urge said armature and follower in the direction they move during operation, whereby to decrease the energy required to overcome the friction of engagement between the said stop portion and the armature and follower, respectively.

9. In a relay of the character described, a coil, a pivoted armature spring biased away from said coil, a pivoted armature follower, a loose lost motion connection between the armature and follower so constructed and arranged that, when the armature is attracted to the coil, it moves part of the distance thereto but in the latter portion of its movement carries the follower with it, and a spring biased contact actuator having a stop engaged by said follower, whereby said follower is released from said stop at least in part by inertia due to initial momentum of the armature.

10. In a relay of the character described, a coil, a pivoted armature spring urged away from the coil, 9. pivoted follower positioned at that side of the armature away from the coil, said follower being spring pressed away from the coil, a loose connection betweenunpivoted ends of the armature and follower, the parts being so constructed and arranged that, when the coil is dc-energized, said armature and follower have their unpivoted ends in contact, but nergization of the coil and attraction of the armature permits a lag in the movement of the follower whereby to separate unpivoted ends of the armature and follower, a spring pressed contact actuator member normally spring-urged ina direction toward said armature and follower but prevented from movement by said follower, said follower releasing said actuator member and said armature engaging said actuator member when the coil is energized to permit partial movement of said actuator member, and said armature releasing said actuaator member to permit continued full movement of the actuator member when the coil is subsequently tie-energized.

11. In a relay of the character described, a coil, a movable contact controlling member, spring means for urging said controlling member in one direction, stop means on said controlling member, a pair of spaced armature members fulcrumed and spring biased away from said coil, projections on said armature members, one of said projections being longer than the other, and a lost motion connection between said armature members, whereby the armature member contiguous to the coil will first move alone on energization of the coil and then, through said lost motion connection, carry the other armature member with it but in spaced relation, the construction and arrangement being such that, in unactuated position, said controlling member is held against movement by the longer of said projections engaging said stop means, energization of said coil will result in releasing said longer projection from said stop means but align the shorter projection therewith whereby to permit said controlling member to move to an intermediate position, and de-energization of said coil and return movement of the armature members will release the shorter projection from said stop means and permit movement of said controlling member to fully actuated position.

12. In a relay of the character described, a coil, a pivoted armature spring-urged away from the coil, a pivoted follower positioned at that side of the armature away from the coil, said follower also being spring pressed away from the coil, and a lost motion connection between unpivoted ends of the armature and follower, the armature, follower and lost motion connection comprising an armature-follower assembly, the parts of said armature-follower assembly being so constructed and arranged that, when the coil is tie-energized, said armature and follower have their unpivoted ends in contact but energization of the coil and attraction of the armature permits a lag in the movement of the follower whereby to separate unpivoted ends of the armature and follower.

ARCHIE J. McMASTER. 

